Door latch



Aug. 6, 1'929. F. M. NELSON i DOOR LATCH Filed Nov. 27, 1922 2Sheets-sheet 1 6/ s J4 55 JF 7'@ f6 62 65 f8 62 Z9 5 d 5a Q3 6/ 'je 64,f 5 5o MM a 32 44 76- 27 2*65 77 60 i E J5 56 'oq 60a' 66 a 1 J/ 4o 4766 \f-.\ 67 5a /F 9 gj 62 59a 59o 69 /4 2/ r62)" /7/3 @if Of'ny.

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DOOR LATCH Filed Nov. 27. 1922 2 sheets-snm 2 j 3 /0 l /QZ /05'v 9 6 /79 v his Attorney.

. there are no unsightly Patented Aug. 6, 1929i FREDRICK AM. NELSON, OFLOS ANGELES, CALIFORNIA.

DOOR LATCH.

Application filed November 2*?, 1922.

The present invention relates generally to door latches, andparticularly it pertains to a mechanism, in combination with a standardtype of door-lock, whereby a door may be leftv ajar and securely heldagainst further openino. In use it is for the purpose of locking thedoor ajar, such as for admitting a greater circulation of air to a room,and so limiting its opening movement as to prevent the unauthorizedentrance l,of intruders.y I

The invention is particularly characterized by a mechanism. which may beautomatically connected with a door, to limit r its opening movement, ordisconnected therefrom, merely by turning the door knob which throws themain bolt; and after being thus connected it cannot be disconnectedtofurthe-r open the door-while the door is open.

The parts are so designed and constructed and the arrangement is suchthat pract-ically all of the parts are concealed from view.; so

attachments exposed to mar the finished appearance of the door -rnd itscasing.

The details of the mechanisms and their arrangement, together withtheirmode of operation, will be more fully set forth in the followingspecification; reference being made therein to the accompanying`drawings, which form a part thereof, and in which:

Fig. 1, is a fragmentary perspective view showing the invention in use;

Fig. 2, is a fragmentary side elevation of the typical door lock withits side removed Fig. 3, is a fragmentary View similar to Figure 2, onlyshowing the parts in different position;

Fig. 4, is a fragmentary sectional elevation illustrating my device inuse and showing the cooperative parts in disconnected relation;

F 5, is a view similar to Fig. 4, only showing the cooperative parts inconnected relation Fig. 6, is a fragmentary transverse vertical sectiontaken as indicated by the line 6-6 of Fig. 5;

Fig. 7, is a fragmentary plan view, taken as indi ated by the line 7 7of Fig. 4: l

Fig. 8, is a sectional plan-view, taken as indicated by the line 8&8 ofFig. 5; and,

cover plate Serial No. 603,650.

of hinges 11, within a door casing, consistY ing of vertical side rails12, and a top rail 13. The numeral 14 designates generally a typicalmortise lock, set into the swinging edge 15 of the door 10; this lockhaving a knob 16 for withdrawing the main bolt 17; the knob 1G having abearing 18 in a cover plate 19, secured to the surface of the door 10.The view shown in Fig. 1 is taken from the inner side of the doorshowing the latter swinging inwardly, and being limited in its opening'movement by my improved device.

Before proceeding to a detail description of the construction andoperation of my improvement, I will first describe the construction andoperation of the lock 14, with vwhich my mechanism is cooperativelyconnected, in order that a clearer understandin may be had of the wholearrangement.

The lock 14 is not claimed as a part of Vmy invention, except only in sofar as it forms a cooperative element by means of which my device isactuated. While the type of door lock .to be hereinafter described willpreferably be used; it is to be understood that my invention is not tobe limited toV use in connection with this specific type of lock, butmay be used in connection with other types of locks which are suitableand applicable to the purpose. VReferring first to Figs. 2 and 3, thenumeral 20 designates a casing in which the moving parts of the lock arehoused; this casing being mounted upon a front relatively thick plate21, by means of which the lock casing is rigidly mounted upon the door10 (Fig. 1), as by means of screws 22; the casing 20 extending into arecess 23, (Figs. 4 and 5) cut inwardly from the edge 24 of the door.The main bolt 17 comprises the usual bevel sided head 25, slidablymounted in an aperture 26 in the front plate 21 and adapted to engagethe vusual complementary locking plate (21) set into the adjacent faceof side rail 12 of the door frame; and a rearwardly extending shank 27.The shank 27 has a bearing between a pair of outwardly extending lugs28, carried upon the side plate 29 of the'casing 20; and an expansiblehelical y.

and 47, of the spring 30, confined between the lugs 28 and head 25,holds the bolt normally in its outward position, as illustrated in Figs.2 and 3. A transversely disposed bar 31 is rigidly secured to the innerend of the shank 27; which bar engages a lug' 32 upon an arm 33 J4 thelatter' being pivotally of a plat-e o4, t mounted upon a pin 35 carriedby theside plate 29 of casing 20. An arm 36 is pivot- Yand it is uponthe outer end of this shaft 41 that the inner door knob 16 is rigidlysecured. An arm 43, of the bell crank 39, has a face 44 which engagesthe lug 32, upon the arm 33 of plate 34; and the other arm 45 has a face46 which engages the shoulder 38 upon the lower end of the arm 36. Theseeral previouslyv described parts are held in their normal positions,as illustrated in Figs. 2 and 3, by the action of the spring 30, andfaces 44 and 46 of arms 43 and 45 engaging lug 32 and shoulder 38,respectively, and also by reason of the bar 31 engaging lug 32 and aface 47 upon arm 43.

The bolt 17 is withdrawn within the plate 21, by rotation of the knob 16in either direction, which, through t-he medium of shaft 41, rotates thebell crank 39. Rotation of the knob 16 to the right, which will throwthe bell crank 39 to the right in Fig. 2, will Y effect a withdrawal ofthe bolt 17, within the case 20, by the engagement of faces 44 arm 43,with lug 32 and bar 31. This effects a rearward movement, (to the rightin Fig. 2) of arm 33 and a raising of the arm 36 and consequently aseparation of the faces 38 and 46. The bolt 17 is in a like mannerwithdrawn by rotation of the knob 16 to the left; throwing the bellcrank 39 to the left in Fig. 2, t-he face 46 of arm engaging theshoulder 38 and moving the arm 36 upwardly; and, by means of its pivotalconnection on the pin 37 rotating the plate 34 tothrow the arm 33 to theright, which carries the bolt with it by the lug 32 engaging the bar 31.

In the present type of lock the door knob onthe outside of the door (notshown) operates independently of the inner door knob 16. The outer doorknob is mounted upon a shaft 48, which has no connection with the shaft41, and rotates independently thereof; a cam 49 being mounted upon theshaft 48 whichis adapted to engage and raise a block 50. The block 5()is mounted vertically slidable between a wall 51, of the case 20, and

a boss 52 formed on the rear plate 29. The block is limited in itsdownward movement by its bottom face 53, engaging a shoulder 54, on thecase 20, and an extension 55, engaging the top edge of the wall 51. Thecenter of the block is recessed, as at 56, to admit of its being' raisedand its upper extremities extended on either side of the hub 40. The topface of the extension 55 is adapted to engage a face 57, on the bottomof the arm 36, below the shoulder 38, to withdraw the bolt 17 throughthe medium of arm 36, plate 34, arm 33, and lug 32, engaging bar 31,when the block 50 is raised by the cam 49, through rotation of the shaft48 by the outer door knob. The action of spring 30, through the variousconnecting media operates to hold the block 5() down upon and incont-act with its seat as above described.

A latch (known as a night latch) is thrown upon the lock 14 to preventthe bolt 17 being' withdrawn by turning the knob from the outside,yetnot interfering with its being drawn by rotation of the knob 16 fromthe inside, by means of a pair of manually operable push pins 58 and 59operatively connected by means of a lever 60. Each of the pins 58 and 59have reduced ends 61 slidingly supported in bearing apertures 62 infront plate 21. The outer ends of the apertures 62 are reamed out toform enlarged depressions to admit of the finger being' inserted thereinwhen pushing the pins inwardly. The reduced ends 61 form shoulders 63which abut against the inner face of plate 21, to limit the outwardmovement of the pins 58 and 59. The inner end of the pin 58 is pivotallyconnected to the upper end of the arm by means of pivot pin 64; whilethe` lower end of the arm 60 is pivotally connected to the pin 59 bymeans of a pin 65, carried by the latter, sliding-ly engaging in a slot66 in the former. The arm 60 is pivotally mounted on the plate 29 bymeans of a pin 60a.

The inner end 67, of the pin 59, is slidingly supported between bearinglugs 68, formed upon the inner face of the case plate 29. This inner end67 of the pin 59 is also adapted, when the pin is moved to the right inFig. 2, to ride over an extension 69, upon the block 50, to hold thelatter against upward movement by rotation of cam 49. In this connectionit might also be mentioned that the lugs 68 also hold the pin 59 againstupward movement, so that when it is in proper position it will rigidlyhold the block 50 against similar movement. Thus when the pins 58 and 59are in the position shown in Fig. 2 the bolt 17 may be withdrawn byrotation of either of the inner or outer knobs upon the shafts 41 and48, respectively; but when they are moved to the relative posiloo tionsillustrated in Fig. 8, with the end 67 overriding the extension 69 thebolt may bc withdrawn only by rotation of the inner knob 16, the outerknob being held against movement to raise the block 50.

The pins 58 and 59 are yicldingly held against movement by means of aleaf spring 59a engaging a V shaped extension 59b on the bottom edge ofthe pin 59.

Proceeding now to the detailed description of my improvement, an arm 70is rigidly mounted upon the inner knob shaft 41, and is so positionedthereon that when the bol is in the position illustrated in Figure 2,that is, its normal latching position, the arm 70 will extend in theposition illustrated in dotted lines in Figs. 4 and 5. A pin 71 in theouter end of the arm 70 engages in an arcuate longitudinal slot 72 inthe lower end of a bar 73; the latter being separably and adjustablyconnected at its upper end to a rod 74 extending downwardly from thelower end of a bolt 75. For convenience of description I willhereinafter refer to the bolt 17 as the main lock bolt and. the bolt 75as the secondary bolt. A pin 76 is carried by the bar 73 which ext-endsthrough a vertically disposed slot 77 in the case plate 29; which pin isadapted to engage in a notch 78 in the lower edge of the pin 58, whenthe latter and the bar 73 are moved to proper positions, the object ofwhich will be hereinafter explained.

The upper end of the bar 7 3 is adjustably and removably connected tothe lower end of the rod 74, by bending the former over, as at 79, andextending the rod 74 through an aperture in this bent over portion, andthen inserting pins 80 through perforations 81 in the rod 74, on either'side of the portion 79.

The bar 73, and rod 74, extend through a channel 82 cut in the edge 24of the door 10, and extending upwardly from the recess 23 to the topedge 83; a guide casing 84 con# taining the secondary bolt 75, being setinto this channel, so that its top edge will be flush with the top edge83 of the door.

The guide casing 84 may be secured in the channel 82 in any suitablemanner. Its front face 85 preferably lies flush with the edge 24 of thedoor 10; a plate 86 being provided to enclose the front open side of thechannel 82. The plate 86 may be secured in place by having an off-setupper end 87 extending to a transverse slot 88 in the bottom 89 of theguide casing 84; the opposite end of this plate beine' also off-set, asat 90, to extend behind and be retained in place by the front plate 21of the lock 14, as shown in Figs. 4 and 5.

The secondary bolt 75 preferably has a square body portion 91, whichforms a close sliding fit in the guide casing 84, and of such length asto have adequate bearing surface. The rod 74 may be attached to the bodyportion 91 in any suitable manner, as, for instance, by screw threadedengagement. The guide casing 84 is slightly larger than the body portion91 on one side, to form a space 92 for the introduction of a leaf spring93; the latter being held against longitudinal movement by engagementwith the bottom 89 and top 85% rlhe spring 93 has a transverselydisposed outwardly extending rib 94 adapted to engage in a complementarynotch 95 in the bodyportion 91, to yieldingl y retain the latter in itsuppermost position.

The guide casing 84 has an aperture 96 in its top end through which theupper end of the secondary bolt 75 extends when moved from the positionshown in Fig. 4 to that shown in Fig. 5. The upper end of the bolt 75 isreduced to form a neel; 97, preferably cylindrical, on the upper end ofwhich is a transversely disposed T-head 98, of substantially the samelength as the corresponding dimension of the body portion 91.

An arm 99 is pivotally mounted at one end, by means of a pivot piny 100,in a bearing frame 101, clearly illustrated in Figs. 1, 4, 5, and 8. Theframe 101 comprises a top plate 102, by means of which it is secured ina recess 103 cut in the bottom face of the top rail 13 of the doorframe, and a downwardly extending back portion 104, which acts as a stopfor the arm 99. A bottoni plate 105, preferably formed integral with thetop plate 102 by means of an end portion 106, extends inwardly from oneend and is spaced from the plate 102 to form an intel'- stice 107, whichconstitutes a bearing for the pivotal end of the arm 99, as shown in n 4and 5. This bearing end of the frame 101 is set into a recess 108, cutin the side rail 12 of the door frame; and is so positioned that theinner end 109 of the plate 105 will be flush with the inner face of therail 12, and the bottom face 110 of the arm 99, will, when in its normalposition within the frame, illustrated in solid lines Fig. 8lie flushwith the bottom face of the top door frame rail 13. The arm 99 isadapted to swing outwardly from the frame 101, upon its pivot, asillustrated in Fig. 1 and in dotted lines in Fig. 8.

The arm 99 has a longitudinal slot 111; so positioned that when the armis in its normal closed position, within the frame 101, as shown in Fig. 8, and the door 10 is closed, this slot will lie directly over theT-head 98 and necl- 97, of the secondary bolt 75; the head 98 being somounted as to extend in direction longitudinal of door 10 and of theslot 111 when the door 1.0 is closed, as shown in Figs. 4 and 5. Theslot 111 may be of any length, depending upon the distance it is desiredto open the door, and is of a width slightly greater than the diameterof the neck 97 on the secondary iso the top edge of the bolt 75; thebottom face of the T-head 98 being spaced from the top tace 112 ot thebody portion 91, a distance slightly greater than the thickness of thearm 99; so that when the tace 112 engages the bottom tace of the arm 99,the bottom tace oi' the E`head will be tree to swing over its top tacewhen the door 10 is moved to the position as shown in Fig. 1, and indotted lines in Fig. 8.

The mechanism is shown in its normal inoperative position in Figa, andin its operative position in Fig. 5 g being yieldingly held in the lastmentioned position by spring 93. The slot 72, in the lower' end of thebar 73, is of such length that after the bar has been moved eitherupwardly or downwardly, by the arm 70, through rotation oi the door knob16, the arm 7 0 may be tree to return to its normal central position,illustrated in dotted lines in Figs. l and 5 which is the position itassumes when the lock bolt 17 also in its normal position, asillustrated in Figs. 2 and 3.

In operation the arm 99 will normally lie in its position in the frame101, as illustrated in solid lines in Fig. 8, and as shown in section inFigs. et and 5, and the secondary bolt 75 and its actuating` mechanismwill be in the position illustrated in Fig. 4:. Bv rotating 'the innerdoor knob 16, and its shaift 4:1, to the right in Figs. 1 and el, thelock bolt 17 may be withdrawn to disengage it :trom its complementarylatching` plate to open the door, without moving the bar 73; as in thisoperation the arm will move 'from the position shown in dotted lines inFig. 4 to that shown in solid lines, the pin 71 moving` in the slot 72,without effecting movement of the bar 7 3. Assuming the parts to bestill in their normal positions, as illustrated in Fig. 4f, rotation ofthe knob 16 to the left in Figs. 1 and 5, to withdraw the bolt 17 fromits complementary locking plate, will move the arm 70 from the positionshown in dotted lines in Fig. 5 to that shown in solid lines, therebycausing the pin 71 to engage the top of the slot 72, raising the boltthrough the medium of bar 73 and rod 75, from the position shown in Fig.i to that shown in Fig. 5. rIhis will raise the bolt 7 5, causing` thel"head 98 to be extended through the slot 111, as illustrated in Figs. 5and 6, so thatwhen the door 10 is open the neck 97 will carry the arm 99with it, swinging it about its pivot 100 to the position illustrated inFig. 1 and in dotted lines in Fig. 8. The F-head 98 is always extendingparallel with the plane of the door 10 and when the door is opened itwill swing to a position transversely of the slot 111, so vthat the twocannot be again disconnected until the door is closed. The bolt 75 maybe disconnected from the arm 99 merely by closing the door 10, whichreturns the arm 99 to its'normal position, and turning the knob 16 tothe right, in Figs. 1 to 5, which will move the parts from the positionshown in Fig. 5 to the position shown in Fig. 1i.

The front tace of the arm 99 has a beveled notch 113 cut in it, and thehead 98 and the neck 97 are bevelled on their rear sides, as at 11e, sothat if the parts are in the position shown in Fig. 5, when the door 10is open they will be moved to the position shown in Fig. et, when thedoor is closed, by reason of the surface 11.4 engaging the surface 113..

ln order that an unauthorized entrance may not be gained from theoutside I provide the notch 78 in the pin 58, so that when these barsare moved to the position shown in F 3 and the bolt 75 raised to theposi- 'tion shown in Fig. 5, to hold the door open as shown in Fig. 1,the pin 76 upon bar 73 will engage in the notch 78, thereby preventingthe shitting of either ot the pins 58 or 59 to remove the end 67 fromits position over the lug extension 69, to permit the knob to be turnedto open the door from the outside.` As the bolt 75 cannot be disengagedtrom the arm 99 while the door 19 is open, this will prevent anyone'trom reaching in zhrough the open door and actuating either et the pins58 or 59 to permit the door toy be opened troni the outside after it hasbeen closed to withdraw the bolt 75 'from the arm 99. ln the type oflock hereinbetore described, wherein the inner and outer door lne-bsoperate entirely independent of each other, thel bolt 75 could not bewithdrawn by rotation et the outer knob on shaft 48, but as this type oflock is also made with the inner and outer knob shafts 41 and Li8operating in conjunction with each other to withdraw the bolt 17, thepin 76 and notch 78 will be effective to thus prevent unauthorizedopening of the door.

l,While I have herein shown and described the prefer 'ed speciticembodiment ot my invention, I nevertheless reserve the right to makesuch changes or moditications in structure as will properly come withinthe scope o't' the appended claims.

Having described my invention, l claim:

1. The combination with a doei.' having a main bolt and means to actuateit, and a door casing, of a member carried by the door and a membercarried by the casing, said members being adapted to interengage onlywhen the door is closed to limit its opening movement, means inconnection with said members to prevent their disengagement when thedoor is open, and means operatively connecting the bolt actuating meanswith one of said members to selectively etlect their interengagement ordisengagement.

2. The combination witha door having a main bolt, means to actuate saidbolt, and a door casing, of an arm carried by the door llO casing, asecondary-bolt carried by the door adapted to interengage with said armto limit the opening of the door; said secondary bolt and arm beingadapted to interengage only when the door is closed; and meansoperatively connecting the main bolt actuating means with the secondarybolt to selectively effect the interengagement of said secondary boltand arm.

3. The combination with a door having a main bolt, means to actuate saidbolt, and a door casing, of an arm carried by the door casing, asecondary bolt carried by the door adapted to interengage with said armto limit the opening of the door; said secondary bolt and arm beingadaptedto interengage only when the door is closed and having means toprevent their disengagement when the door is open; and means operativelyconnecting' the main bolt actuating means with the secondary bolt toselectively effect the interengagement of said secondary bolt and arm.

4. The combination with a door having a main bolt means operable inopposite directions to withdraw said bolt, and a door casing, of amember carried by the door casing, a member carried by the door, saidmembers being adapted to interengage to limit the opening of the door;and means operatively connecting the main bolt actuating means and oneof said members to positively effect their interengagement anddisengagement by the bolt withdrawing means; said last mentioned meansbeing arranged to permit selective interengagement or disengagement ofsaid member by moving the main bolt withdrawing means in one directionor the other.

5. The combination with a door having a main bolt, means operable inopposite directions to withdraw said bolt, and a door casing, of an armcarried by the door casing, a secondary bolt carried by the door, saidsecondary bolt and arm being adapted to interengage to limit the openingof the door; andmeans operatively connecting the main bolt actuatingmeans and said secondary bolt to positively effect its interengagementwith said arm; said last mentioned means being arranged to permitselective interengagement or disengagement of said secondary bolt andarm by moving the main bolt withdrawing means in the proper direction.

6. The combination with a door having' a main bolt, means operable inopposite directions to withdraw said bolt, and a door casing, of an armcarried by the door casing, a secondary bolt carried by the door; saidsecondary bolt and arm being adapted to interengage to limit the openingof the door and having means to prevent their disengagement when thedoor is open; and means operatively connecting the main bolt actuatingmeans and said secondary bolt to effect its interengagement with saidarm; said last mentioned means being arranged to permit selectiveinterengagenient or disengagement of said secondary bolt and arm bymoving the main bolt withdrawing means in the proper direction.

7. The combination with a door having a main bolt, means operable inopposite directions to withdraw said bolt, and a door casing, of an armcarried by the door casing, a secondary bolt carried by the door, saidsecondary bolt and arm being adapted to intergage only when the door isclosed to limit the opening of the door and having means to preventtheir disengagement when the door is open; and means operativelyconnecting the main bolt actuating means and said secondary bolt topositively effect its interengagement with said arm; said last mentionedmeans being arranged to permit selective interengagement ordisengagement of said secondary bolt and arm by moving the main boltwithdrawing means in the proper direction.

8. rIhe combination with a door having a main bolt, means operable inopposite directions to withdraw said bolt, and a door casing, of an armcarried by the door casing, a secondary bolt carried by the door, saidsecondary bolt and arm being adapted to interengage to limit the openingof the door; and means operatively connecting the main bolt actuatingmeans and said secondary bolt to effect its interengagement with saidarm; said last mentioned means being arranged to permit selectiveinterengagement or disengagement of said secondary bolt and arm bymoving the main bolt withdrawing means Y in the proper direction and towithdraw the main bolt without actuating bolt.

9. The combination with a door and its casing of a main bolt on thedoor; inner and outer knobs on the door rotatable to withdraw said bolt;latching means in connection with said main bolt and knobs toselectively prevent withdrawal of the bolt by rotation of the outerknob; an arm pivotally mounted on the casing; a secondary bolt carriedby the door adapted to engage said arm to limit the opening of the door;means operatively connecting the inner knob with said secondary bolt toeffect its engagement with and disengagement from said arm; and means toprevent operation of the latching means to permit rotation of the outerknob to withdraw the main bolt while the secondary bolt is in engagementwith the arm.

lO. The combination with a door and its casing of a main bolt on thedoor; inner and outer knobs on the door rotatable to withdraw said bolt;latching means in connection with said main bolt and knobs toselectively prevent withdrawal of the bolt by rotation of the outerknob; an arm pivotally mounted said secondary on' the casing; asecondary bolt carried by the door adapted to engage said arm, only Whenthe door is closed, to limit the opening of the door, and having meansto prevent its disengagement therefrom When the door is open; meansoperatively connecting the inner knob With said secondary bolt to eiectits engagement with and disengagement from said arm; and means inconnection With said connecting means to prevent operation of thelatching' means to permit rotation of the outer knob to Withdraw themain bolt while the secondary bolt is in engagement With the arm.

11. The combination with a door and its casing of a main bolt on thedoor; inner. vand outerknobs on the door rotatable to Withdraw saidbolt, the inner knob being operable to Withdraw the bolt by rotation inopposite directions; latching means in connection with said main boltand knobs to selectively prevent Withdrawal of the main bolt by rotationof the outer knob, said latching means being positioned to beinaccessible for operation When the door is closed; an arm igvaaoes:

pivotally mounted on thecasing; asecondary bolt carried by the dooradopted to engage said arm, only When,tlie door is closed, to limit theopening of the door, and having means to prevent its disengagementtherefrom When the door is open; means 0peratively connecting the innerknob 'With said secondary bolt to effect its engagement With anddisengagement from said arm; means in connection with said connectingmeans to prevent operation of the latching means to permit Withdrawal ofthe main bolt by rotation of the outer knob While the secondary bolt isin engagement With said arm; the said connecting means being arranged topermit selective engagement or disengagement of said secondary bolt withsaid arm simultaneously With the Withdrawal of the main bolt by rotationof the inner knob in the proper direction.

ln Witness that I claim the foregoing I have hereunto subscribed my namethis 2nd day of November, 1922.V

FREDRICK M. NELSON

